Refactor away deprecated homekit_controller test helpers

[Jc2k]

Proposed change

This is a test only change to remove some test helper classes - FakePairing and FakeController. Upstream has better implementations which we are already using in the config flow tests, this just finishes the migration.

This is a precursor to my branch to enable support for HomeKit push events (don't want to re-implement a bunch of test infrastructure downstream).

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

The integration reached or maintains the following Integration Quality Scale:

• No score or internal
• 🥈 Silver
• 🥇 Gold
• 🏆 Platinum

[codecov]

Codecov Report

Merging #32177 into dev will increase coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##              dev   #32177      +/-   ##
==========================================
+ Coverage   94.75%   94.75%   +<.01%     
==========================================
  Files         768      768              
  Lines       55639    55639              
==========================================
+ Hits        52721    52722       +1     
+ Misses       2918     2917       -1

Impacted Files	Coverage Δ
homeassistant/helpers/entity.py	97.64% <0%> (+0.33%)	⬆️

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